e/Eikonal equation

Information
has gloss	eng: The eikonal equation (from German Eikonal, which is from Greek εἰκών, image ) is a non-linear partial differential equation encountered in problems of wave propagation, when the wave equation is approximated using the WKB theory. It is derivable from Maxwell's equations of electromagnetics, and provides a link between physical (wave) optics and geometric (ray) optics.
lexicalization	eng: eikonal equation
instance of	(noun) a mathematical statement that two expressions are equal equation

Meaning
French
has gloss	fra: En optique géométrique, léquation eikonale ou iconale, est léquation fondamentale régissant le trajet de la lumière dans un milieu. Elle permet de démontrer toutes les autres lois, telles que les lois de Snell-Descartes et de déterminer les trajectoires des rayons lumineux.
lexicalization	fra: Equation eikonale
lexicalization	fra: Équation eikonale
Japanese
has gloss	jpn: 幾何光学において、アイコナール方程式は光の伝播をあらわす基礎方程式である。
lexicalization	jpn: アイコナール方程式
Russian
has gloss	rus: Уравнение эйконала — это нелинейное дифференциальное уравнение в частных производных. Может быть представлено в форме:
lexicalization	rus: Уравнение эйконала